Manufacture of multiple contact devices



Dec. 25, 1962 s. T. DEAKIN 3,069,751

MANUFACTURE OF MULTIPLE CONTACT DEVICES Filed Oct. '7, 1958 Inventor:

STANLEY THOMAS DEAKIN Attorneys United States Patent Ofilice 3,069,751Patented Dec. 25, 1962 3,069,751 MANUFACTURE OF MULTIPLE CONTACT DEVICESStanley Thomas Deakin, Ewell West, England, assignor to AssociatedElectrical Industries (Woolwich) Limited, a British company Filed Oct.7, 1958, Ser. No. 765,764 Claims priority, application Great BritainOct. 10, 1957 4 Claims. (Cl. 29155.5)

This invention relates to the manufacture of multiple contact devices ofthe kind in which an array of contacts is embedded in recesses orapertures in an insulating base member in accordance with apredetermined pattern.

The invention has an important application in socket contacts forplug-in type components, such as thermionic valves and transistors, usedin printed circuits.

Printed circuits are usually formed on an insulating panel and thesocket contacts pressed into apertures cut in the panel and held thereby the resilience of the contact. Valve sockets for instance will beusually arranged around a pitch circle whilst sockets for othercomponents will be arranged in appropriate patterns.

Normally in apparatus such, for instance, as a radioreceiver employingprinted circuitry, there will be a number of components and hence thefitting of the socket contacts into the aperture on the insulating boardcan be a lengthy and laborious operation adding appreciably to the costof production.

The object of the present invention is to provide an improved method ofinserting contact members within an insulating body.

According to the present invention a method of inserting contact memberswithin apertures arranged in a pattern in a body of insulating materialcomprises the steps of pressing said contact members in accordance withsaid pattern on a strip of material having an adhesive surface, placingsaid strip of material over said body so that said contact members arealigned with said apertures, placing each of said contact members intothe corresponding aperture so that said contact members are retainedwithin said apertures and removing said strip of material so as to leavesaid contact members within said apertures.

The contact members may be arranged in repetitive groups on the adhesivesurface.

The contact members may be fed through a plurality of ducts on to theadhesive surface, the outlet ends of which ducts are arranged in therequired pattern so that the contact members, as fed on to the adhesivesurface, conform to the required pattern. The strip of material may befed continuously or in steps across the ends of the ducts.

In order that the invention may be more readily understood referencewill now be made to the accompanying drawing in which:

FIG. 1 is an illustration of apparatus used for affixing contact membersto a strip of material having an adhesive layer on one surface;

FIG. 2 is a perspective view of the strip with the contact membersadhering to one surface in accordance with a required pattern, and

FIG. 3 is a side view, sectioned, of an apertured plate illustrating howthe contact members are pressed into the apertures.

With reference to FIG. 1 a strip of flexible material 1, which may beplastic, cloth, paper or any other suitable material, is wound off adrum 2. The strip of material 1 has a layer of adhesive material 3 onits upper surface. This adhesive material may be of any suitable type.One type which has been found satisfactory in use is a mixture of pitch,wood ash and tallow in the ratio 511:1.

The tallow is mixed with the pitch and the wood ash is addedsubsequently. This mixture is placed in a layer on a strip ofmaterial 1. If the mixture is subsequently added it becomes tacky andadhesive.

The strip 1 is pressed under a guide roller 4 and over a roller 5 whichmay be heated so as to apply heat to the adhesive material if required.Heat may be supplied to the roller 5 by means of hot air or other fluidflowing through a duct 6 from a suitable source of heat. The strip 1then passes over a block 7 which has an upper surface 8. A plurality ofducts 9 are located above the surface 8 and are supported in a holder11. The ducts 9 are arranged in accordance with the required pattern ofcontact members. The contact members are fed one by one in successiondown each of the ducts 9 and on to the upper surface of the adhesivelayer 3 on the strip 1 and adhere thereto. The strip 1 is subsequentlypressed over the roller 12. As the strip 1 passes under the ducts 9contact members drop down so as to adhere to the layer 3 in the requiredpattern and groups of contact members 14 are formed at successivepositions on the strip 1 as the strip 1 moves across the ends of theducts under the action of the rollers.

After the contact members have been aflixed to the layer 3 it may benecessary to store the strip 1 before the contact members are insertedwithin the apertures of a printed circuit. It will therefore beconvenient to roll up the strip to store it. If the strip is rolledmeans must be provided to prevent the adhesive layer 3 from adhering toother protions of the strip and also to prevent damage to the contactmembers. For this surface, after the contact members have been placed inposition, the adhesive layer may be coated with a layer of French chalkor other absorbent powdered material or a layer of paper may be placedover the portion of the adhesive layer not covered by the contactmembers. Alternatively a sheet of foam rubber or other compressiblematerial may be placed on the adhesive layer so as to extend either instrips transverse to the strip 1 and between each successive groups ofcontact mmbers, or in strips encircling each group, or in one or morestrips extending longitudinally along the strip 1 outside each group ofcontact members. This is illustrated in FIG. 2 which shows twolongitudinally extending strips of foam rubber 15, 16 extending one oneach side of the groups of contact members 14. As an alternative, or inaddition to, the strips 15, .16, transversely extending strips 17 may beplaced between the groups of contact members. The strips of compressiblematerial 15, 16 may conveniently be applied to the strip 1 as shown inFIG. 1 by unwinding the strips of compressible material from a drum 18.Only one strip 15 is illustrated in the figure.

When the strips of rubber or other compressible material, or otherprotective devices as described above are in position on the strip 1,the strip, with the contact members 14, may be rolled up and storeduntil required for use, the thickness of the compressible materialpreventing damage to the contact members and also preventing theadhesive layer from sticking to portions of the strip.

FIG. 3 illustrates how the contact members are in serted in apertures ina printed circuit board, or other board of insulating material havingapertures of a certain pattern. The board 21 is shown in section throughthe apertures 22. The contact members 14, which are shown as sockets butmay, of course, be any suitable type of pin, socket or connector, adhereto the surface of the layer 3 and are placed over the correspondingapertures 22 of each group and are then pressed into the apertures bythe action of an operators thumb 23 or by other suitable means. Thecontact members are so shaped with lips 24 and flanges 25 that they areretained within the apertures 22 by the action of the lips and theflanges engaging respectively with opposite surfaces of the plate 21.The strip of foam rubber is compressed as the contact members arepressed in the apertures and prevents the adhesive layer 3 from.adhering to the upper surface of the plate 21. The use of French chalkor paper as described above will also prevent the adhesive layer 3 fromadhering to the plate 21.

When the contact members are retained in position within the aperture 22the strip 1 is removed from the upper surfaces of the flanges 24 leavingthe contact members in position Within the apertures. The strip 1 isfirst laid over the surface of the plate 21 so that the contact membersmay be pressed into each group of apertures. The method of inserting thecontact members is quick and accurate and greatly decreases the timetaken to construct a printed circuit. The plate 21 may be the body of avalve holder or other insulated body into apertures in which contactmembers are to be inserted. The strip 1 may, of course, be cut intopieces after the contacts have been pressed on the adhesive layer.

A pressure sensitive adhesive sheet material, for example that soldunder the name Sellotape, a registered trademark, may be used for thestrip 1 and this is of such a type that it is easily removed from thecontact members when the contact members have been placed in positionWithin the apertures. The adhesive layer 3 may not be applied to thewhole of the surface of the strip 1 but may only extend over theportions of the surface to which the contact members are required toadhere. The material of the adhesive layer is applied by any suitablemethod well known in the art.

The strip 1 may be moved continuously or in strips across the ends ofthe ducts 9. The contact members may be fed on to the strip 1 from belowif required and in this case the adhesive layer will have to be coatedon to the lower surface of the strip 1.

The invention may be employed for inserting contacts of the typedescribed in co-pending patent application Serial No. 749,673 in aninsulating panel for a printed circuit.

What I claim is:

1. The process of manufacturing multiple electrical contact devicescomprising the steps of placing in accordance with a required pattern onan adhesive surface of a strip of material a plurality of contactmembers of the type adapted to be self-retaining in suitably shapedapertures, placing non-adhesive compressible material having a thicknessgreater than the height of said contact members onto said adhesivesurface adjacent to said contact members, placing said strip of materialover an insulating body formed with apertures arranged in accordancewith the required pattern so that said compressible material iscompressed and said contact members are inserted into respectiveapertures and retain themselves therein and finally removing said stripof material together with said compressible material from said contactmembers so as to leave said contact members within said apertures.

2. The process of manufacturing multiple electrical contact devicescomprising the steps of placing in accordance with a required pattern onan adhesive surface of a strip of material a plurality of contactmembers of the type adapted to be self-retaining in suitably shapedapertures, placing non-adhesive compressible material having a thicknessgreater than the height of said contact members onto said adhesivesurface between at least some of said contact members, placing saidstrip of material over an insulating body formed with apertures arrangedin accordance with the required pattern so that said compressiblematerial is compressed and said contact members are inserted intorespective apertures and retain themselves therein and finally removingsaid strip of material together with said compressible material fromsaid contact members so as to leave said contact members within saidapertures.

3. The process of manufacturing mulitple electrical contact devicescomprising the steps of placing in accordance with a required pattern onan adhesive surface of a strip of material a plurality of contactmembers of the type adapted to be self-retaining in suitably shapedapertures, placing non-adhesive compressible material having a thicknessgreater than the height of said contact members on said adhesive surfaceso that said compressible material extends longitudinally along saidstrip adjacent to said contact members, placing said strip of materialover an insulating body formed with apertures arranged in accordancewith the required pattern so that said compressible material iscompressed and said contact members are inserted into respectiveapertures and retain themselves therein and finally removing said stripof material together with said compressible material from said contactmembers so as to leave said contact members within said apertures.

4. The process of manufacturing multiple electrical contact devicescomprising the steps of placing in accordance with a required pattern onan adhesive surface of a strip of material a plurality of contactsmembers of the type adapted to be self-retaining in suitable shapedapertures, placing non-adhesive compressible material having a thicknessgreater than the height of said contact members onto said adhesivesurface adjacent to said contact members, rolling up said strip so thatthe free surface of said compressible material abuts against anon-adhesive surface on said strip and protects said contact members,unrolling said strip, placing said strip of material over an insulatingbody formed with apertures arranged in accordance with the requiredpattern so that said compressible material is compressed and saidcontact members are inserted into respective apertures and retainthemselves therein and finally removing said strip of material togetherwith said compressible material from said contact members so as to leavesaid contact members Within said apertures.

References Cited in the file of this patent UNITED STATES PATENTS2,251,326 Cullin Aug. 5, 1941 2,281,478 Chirelstein Apr. 28, 19422,676,765 Kaplan Apr. 27, 1954 2,768,429 Willis Oct. 30, 1956

